1. Field of the Preferred Embodiment(s)
This invention generally relates to a pointing device for controlling the positioning, movement and operation of a cursor on a display screen. Specifically, there is a pointing device that uses a single piezoelectric element to indicate movement in three axes.
2. Background of the Invention
Manufacturers of portable laptop computers, recognizing the need for placing the cursor controlling device in a permanent and more convenient location, installed a small stubby, button-like joystick centrally around the keys of the computer keyboard, specifically at the juncture of the "g," "h" and "b" keys of the standard "QWERTY" keyboard. The joystick, also known as a pointing stick, was sensitive to lateral pressure, the amount and direction of which were sensed and input into the computer to cause movement of the cursor, and the speed and direction of cursor movement corresponded to the amount and direction of pressure on the joystick. That manufacturer may also provide two upwardly extending "mouse" or "click" buttons immediately below the space bar.
These pointing sticks utilize resistors or strain gauge resistors to sense changes in movement of the stick. The resistors suffer from several problems. First, they are sensitive to changes in temperature. Second, the resistance change as they are moved is very small which causes difficulty in sensing the amount of position change and which requires amplification circuitry to be placed close to the pointing stick.
Further, despite the advantages of prior art cursor controls, they have been difficult to economically manufacture. In particular, providing the electrical connections between the resistors and the flexible cable which connects to a computer mother board has been complicated and expensive. Therefore, there is a current unmet and heretofore long felt need for a pointing stick, that has a large output signal and is easily manufactured.
3. Description of Related Art
Examples of patents related to the present invention are as follows, and each patent is herein incorporated by reference for the supporting teachings:
U.S. Pat. No. 5,748,180, is a pointing device for controlling cursor movement on display.
The foregoing patents reflect the state of the art of which the applicant is aware and are tendered with the view toward discharging applicant's acknowledged duty of candor in disclosing information that may be pertinent in the examination of this application. It is respectfully stipulated, however, that none of these patents teach or render obvious, singly or when considered in combination, applicant's claimed invention.